With age, a large percentage of the population develops atherosclerotic arterial obstructions resulting in diminished blood circulation. The disturbance to the blood flow that these obstructions cause may induce blood clots which further diminish or block the blood flow. When this process occurs in the coronary arteries it is referred to as a "heart attack". Presently such obstructions are circumvented surgically by grafting a bypass or they are treated by a catheter equipped with a balloon which is inserted through the arterial system, over a flexible guide wire assembly, into the obstruction and then inflated to expand the obstruction's lumen, a procedure known as angioplasty.
Angioplasty, which breaks up but does not remove the obstruction material out of the arterial system, creates an irregular lumen which tends to partially recoil after the balloon is deflated and withdrawn. To lessen this phenomena a stent may be placed in the blood vessel to provide support (further information on intravascular stents is available in chapter 56 of the 2nd edition of a book titled Endovascular Surgery by Samuel S. Ahn and Wesley S. Moore, which was published in 1992 by W. B. Saunders Co. which is hereby incorporated by reference).
Stents may also be useful in other vessels of the human anatomy, therefore, the term "vessel" as used hereinafter shall mean a tubular fluid conduit in the body such as blood vessels and biliary ducts. For example, stents may be inserted in narrowed biliary ducts to keep these ducts open for bile drainage (further information on biliary stents is available in chapter 7 of the 3rd edition of a book titled Practical Gastrointestinal Endoscopy by Peter B. Cotton and Christopher B., Williams, which was published by Blackwell Scientific Publications which is hereby incorporated by reference).
The stent itself, however, may become obstructed. An objective of the present invention is to provide a stent unclogging method and hardware for reopening and cleaning obstructed stents.
These and other objectives of the invention will become apparent from the following discussion and the accompanying drawings.